The present invention relates in general to devices for helping individuals to walk, and in particular to a new and useful orthosis which can produce walking movements in the legs of a paraplegic.
In the United States, there are approximately 250,000 paraplegics. The main causes of paraplegia are spina bifida, muscular dystrophy, and accidents.
In addition to the obvious result of paraplegia, namely the loss of an individual's ability to walk, the paraplegic suffers additional physiological and psychological damage, due to the fact that the individual is constantly lying down or sitting. The physiological problems include deterioration of muscles, bones and some organs. The psychological problems include the fact that the paraplegic must always look up at others. This is particularly distressing and demoralizing to small children.
A variety of solutions have been proposed to overcome the foregoing problems.
One of these solutions is a simple brace which can hold the paraplegic in an upright standing position. This device is marketed under the trade name Parapodium, by the firm of Durr-Fillaur. The Parapodium is nothing more than a fixed pedistal which provides no ambulatory capacity to the wearer.
Other solutions are also known which utilize driven or non-driven, articulated braces to aid in the walking of paraplegics, amputees and other persons with impaired walking ability.
U.S. Pat. No. 1,351,955 to Lowry discloses a battery and motor driven knee joint for swinging the lower leg portion of a full leg prosthesis, to the rear around an artificial knee joint, to simulate a normal walking movement for the artificial leg. The wearer is assumed to have one fully functional natural leg.
U.S. Pat. No. 2,010,482 to Cobb discloses a drive orthopedic brace which is meant to be strapped to the two legs of a crippled person. A crank near the hip is rotated for driving the leg braces to produce a walking movement. The crank rotates a pair of cam mechanisms which alternately swing the upper leg portions of the brace. With each swinging movement, lower stirrups engaged under the feet of the wearer are drawn upwardly to shorten the effective length of the leg and produce a more natural walking movement. Except for strapping the upper and lower legs of the wearer to upper and lower leg portions of the braces, no special mechanism is provided for insuring a correct bending of the knee during the walking operation.
U.S. Pat. No. 2,573,866 to Murphy discloses full leg braces for a paraplegic which have both hip and knee joints with automatic releases for simulating the correct articulation of the legs during a walking movement. Power is provided by the paraplegic who shifts his or her weight from side to side with the aid of crutches which are used in conjunction with the braces. While the knee joints can be released during each step, and this may reduce the amount of so called "hip tuck" movement which is required for braces having locked knees, no mechanism is provided in this reference for powering the rearward swinging of the lower leg. "Hip tuck" movement is required for manipulating the reciprocating gait orthosis of U.S. Pat. No. 4,697,808 to Larson et al., for example, which shows another walking aid.
U.S. Pat. No. 2,210,269 to Taylor discloses a rolling carriage having a complex linking mechanism for artificially producing leg and foot articulation to aid in the rehabilitation of patients suffering from motor loss of the lower limbs, for example motor loss due to infantile paralysis.